Trace analyte collection swab

ABSTRACT

A trace analyte collection swab having a collection surface at least partially coated with a microscopically tacky substance to enhance pick-up efficiency is described. In embodiments, the truce analyte collection swab comprises a substrate including a surface having a trace analyte collection area and a coating disposed on the surface of the substrate in the trace analyte collection area. The coating is configured to be microscopically adhesive to collect particles of the trace analyte from a surface when the trace analyte collection area is placed against the surface. In one embodiment, the coating comprises Polyisobutylene.

This application is a continuation of U.S. patent application Ser. No.14/778,293, filed Sep. 18, 2015, titled “TRACE ANALYTE COLLECTION SWAB,”which is a national stage application, filed under 35 U.S.C. § 371, ofInternational Patent Application No. PCT/CA2014/050200, filed on Mar.10, 2014, titled “TRACE ANALYTE COLLECTION SWAB.” This internationalapplication further claims the benefit of U.S. Provisional ApplicationNo. 61/802,890, filed Mar. 18, 2013, titled “TRACE ANALYTE COLLECTIONSWAB.” U.S. Ser. No. 14/778,293, PCT/CA2014/050200, and U.S. 61/802,890are herein incorporated by reference in their respective entireties.

BACKGROUND

Trace analyte detection is the detection of small amounts of analytes,often at nanogram to picogram levels. Trace analyte detection hasnumerous applications. For example, trace analyte detection can beparticularly useful for security applications, such as screeningindividuals or items for components in explosive materials, narcotics orbiological contaminants where small amounts of these components aredeposited on the individual or on the outside of a package or bag. Avariety of different techniques can be used for trace analyte detection.These methods include ion mobility spectrometry (IMS), massspectrometry, gas chromatography, liquid chromatography, and highperformance liquid chromatography (HPLC).

SUMMARY

A trace analyte collection swab having a collection surface at leastpartially coated with a microscopically tacky substance to enhancepick-up efficiency is described. In embodiments, the trace analytecollection swab comprises a substrate including a surface having a traceanalyte collection area and a coating disposed on the surface of thesubstrate in the trace analyte collection area. The coating isconfigured to be microscopically adhesive to collect particles of thetrace analyte from a surface when the trace analyte collection area isplaced against the surface. In one embodiment, the coating comprisesPolyisobutylene.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingFigures. The use of the same reference number in different instances inthe description and the figures may indicate similar or identical items.

FIG. 1 is a top plan view illustrating a trace analyte collection swabin accordance with an example embodiment of the present disclosure.

FIG. 2 is side elevation view of the trace analyte collection swab shownin FIG. 1.

FIGS. 3, 4, and 5 are partial top plan views illustrating trace analytecollection swabs in accordance with an example embodiment of the presentdisclosure, wherein the coating is patterned.

FIGS. 6 and 7 are partial top plan views illustrating trace analytecollection swabs in accordance with an example embodiment of the presentdisclosure, wherein the substrate has a first color and the coating hasa second color different than the first color.

FIG. 8 is an isometric view illustrating a trace analyte collection swabdispensing system in accordance with an example embodiment of thepresent disclosure, wherein a releasable adhesive is disposed on thesurfaces of respective substrates to detachably join the respectivesubstrates to an adjacent substrate in a stacked configuration.

FIG. 9 is an isometric view illustrating a trace analyte collection swabdispensing system in accordance with an example embodiment of thepresent disclosure, wherein a plurality of substrates are attached in aroll, and wherein respective ones of the plurality of substrates arejoined end-to-end via a perforated section within the roll.

FIG. 10 is an isometric view illustrating a trace analyte collectionswab in accordance with an example embodiment of the present disclosure,wherein the substrate of the trace analytic collection swab comprises aportion of a document such as an airline boarding pass, a ticket, and soforth.

FIG. 11 is an isometric view illustrating a trace analyte collectionswab in accordance with an example embodiment of the present disclosure,wherein the substrate of the trace analyte collection swab comprises aportion of a package.

FIG. 12 is a top plan view illustrating a trace analyte collection swabin accordance with an example embodiment wherein the substrate comprisesthree-dimensional substrate having a generally triangular shape that isrolled into a cone prior to use.

FIG. 13 is a top plan view illustrating a trace analyte collection swabin accordance with an example embodiment of the present disclosure,wherein the swab comprises a brush.

DETAILED DESCRIPTION Overview

The collection (or harvesting) efficiency of trace analyte collectionswabs varies for different chemicals being collected, for the swabmaterial being used, and for different surfaces being swabbed. In someinstances, the efficiency of collection of trace analytes from a surfaceusing a conventional collection swab can be very low or zero for somechemicals. For example, where swabs made from NOMEX or Sharkskinmaterials are used to collect Trinitrotoluene (TNT), a dry chemical,from a vinyl (e.g., “leatherette”) surface, the collection or harvestingefficiency is virtually zero (0) even at fifty (50) times the minimumalarm level capability of a conventional detector.

Consequently, it is desirable to improve the collection efficiency ofconventional swabs. The National Institute for Science and Technology(NIST) described a method of increasing the collection efficiency oftwenty-four micrometer (24 μm) polymeric spheres doped with one-halfpercent (0.5%) explosive. The method described used a tacky (to thetouch) silicone material CV31161 manufactured by NuSil. NIST obtainedsignificant improvement in pickup efficiency for the polymer spheresusing the silicone tacky material. However, the use of NuSil CV/3-1161silicone at 5% loading on the swab surface leaves behind discerniblestreaks of silicone on the substrate surface following swabbing. Whencoating material is left behind on the sampled substrate, the collectedexplosive may also be left behind on the surface. Additionally, NuSilCV3-1161 and similar two-part adhesives are difficult to use, in thatsuch two-part adhesives require that precise quantities of the polymerbase and the catalyst be thoroughly mixed prior to application.Moreover, the catalyst must be stored at below freezing (<0 C.)temperatures. Further, the pot-life of the mixed silicone adhesive isshort—on the order of a few hours. Still further, the final coating ofthe adhesive must be cured at an elevated temperature. NuSil CV3-1161and other 2-part adhesives also contain a peroxide catalyst which is ahazardous substance.

Accordingly, a trace analyte collection swab having a collection surfaceat least partially coated with a microscopically tacky substance toenhance pick-up efficiency is described. In embodiments, the traceanalyte collection swab comprises a substrate including a surface havinga trace analyte collection area and a coating disposed on the surface ofthe substrate in the trace analyte collection area. The coating isconfigured to be microscopically adhesive to collect particles of thetrace analyte from a surface when the trace analyte collection area isplaced against the surface.

In embodiments, the coating comprises Polyisobutylene (PIB). The coatingmay be applied in a pattern on the substrate in the trace particlecollection area. The pattern may comprise one or more first areas wherethe coating is applied and one or more second areas where the coating isnot applied. The one or more first areas are configured to collectparticles of a trace analyte of a first type, while the one or moresecond areas are configured to collect particles of a trace analyte of asecond type that are collected with a low collection efficiency, or thatare not collected by the at least one first area. In embodiments, thesubstrate has a first color and the coating has a second color, whereinthe second color is different than the first color.

In embodiments, the coating includes a dopant. The dopant may comprise acalibrating material for calibration of a detector. The dopant maycomprise a reactant material configured to combine with a trace analytewhen the swab is placed against a surface. The dopant may comprise atracer material that can be used to indicate characteristics of theswab. The dopant may comprise a vapour-collecting material configured tocollect particles of a trace analyte in vapour form.

In embodiments, the substrate comprises paper, filter paper (e.g.,SHARKSKIN filter paper manufactured by Whatman Corporation), an aramidpolymer material (e.g., NOMEX material manufactured by E.I. du Pont deNemours and Company), and so forth. The substrate may be attached to asampling wand. In other embodiments, the substrate comprises one or morebristles of a brush. The substrate may be provided with an identifiersuch as a barcode, Radio Frequency Identification (RFID) tag, and soforth, for furnishing identification of the swab. For example, in anembodiment, the substrate comprises a portion of a document such as aboarding pass, ticket, and so forth. The boarding pass may include anidentifier such as a bar code configured to associate the particles of atrace analyte collected by the coating with the holder of the boardingpass. Similarly, in another embodiment, the substrate comprises aportion of package. The package may include a bar code configured toassociate a trace analyte collected by the coating with the mailerand/or recipient of the package.

In embodiments, a plurality of substrates may be detachably joinedtogether in a trace analyte collection swab dispensing system configuredto dispense individual swabs.

Example implementations of trace analyte detection swabs will now bedescribed with reference to the accompanying drawings.

Example Implementations

FIGS. 1 through 9 illustrate trace analyte collection swabs 100 inaccordance with example embodiments of the present disclosure. As shown,the trace analyte collection swabs 100 comprise a substrate 102including a surface having a trace analyte collection area 104 and acoating 106 disposed on the surface of the substrate 102 in the traceanalyte collection area 104. In embodiments, the coating 106 may bedisposed on the surface of the substrate 102 by coating the coatingmaterial onto the surface, depositing the coating material onto thesurface, spraying the coating material onto the surface, soaking thecoating material into the substrate 102 through the surface,combinations thereof, and so forth. Thus, a coating 106 disposed on thesurface of the substrate 102 of a trace analyte collection swab 100 maybe placed on the surface of the substrate 102 and/or may be soaked intothe surface of the substrate 102.

In embodiments, the substrate 102 comprises a suitable substratematerial such as paper, filter paper (e.g., SHARKSKIN filter papermanufactured by Whatman Corporation), an aramid polymer material (e.g.,NOMEX material manufactured by E.I. du Pont de Nemours and Company), andso forth. The substrate 102 may be configured to be received by achemical/explosives detector which may employ any of a variety ofdetection technologies including: ion mobility spectrometry (IMS), massspectrometry, gas chromatography, liquid chromatography, highperformance liquid chromatography (HPLC), combinations thereof, and soforth. For example, in the embodiment shown, the substrate 102 comprisesa generally rectangular strip of the substrate material (e.g., paper,filter paper, aramid polymer material, etc.) which may be placed againsta surface to collect particles of one or more trace analytes, and theninserted into a detector where collected particles arc desorbed. In aspecific example of this embodiment, the substrate 102 may comprise astrip of substrate material having a length of 6.35 cm (2.5 in) and awidth of 2.54 cm (1 in). In this example, the substrate material maycomprise paper having a paper weight of approximately 80 gsm (20 lb).However, it is contemplated that the substrate material may comprisepapers having paper weights greater or less than 80 gsm (20 lb).Moreover, it is contemplated that the substrate material may alsocomprise filter paper, an aramid polymer material, combinations thereof,and so forth. Further, it is contemplated that the substrate 102 mayhave other shapes (e.g., square, oval, triangular, circular, irregular,etc.). The surface of the substrate 102 can be smooth or roughened.

In embodiments, the substrate 102 may be configured for attachment to asampling wand. For example, an adhesive may be disposed on the surfaceof the substrate opposite the coating 106 (e.g., on the reverse side ofthe trace analyte collection area 104 of the substrate 102) tofacilitate attachment of the swab 100 to and/or removal of the swab 100from a sampling wand (not shown).

The coating 106 is configured to be microscopically adhesive to collectparticles of the trace analyte from a surface when the trace analytecollection area 104 is placed (e.g., pressed) against the surface. Inembodiments, the coating comprises Polyisobutylene (PIB) having aformulation such as PIB 4T or other PIB formulations. The PIB may have amolecular weight of approximately 59,000 GPC (Gel PermeationChromatography). PIB (e.g., PIB 4T or other NB formulation) is nothazardous to humans or animals, can be stored at room temperatureindefinitely, readily dissolves in hexane, is stable in solution, andhas substantially no pot-life.

The coating 106, which, in embodiments, comprises PIB (e.g., PIB 4T orother NB formulation), is not perceptibly tacky or sticky (e.g., thecoating 106 is dry-to-the-feel) and does not adhere to the surface beingsampled, but is microscopically adhesive (e.g., microscopically stickyor tacky) to particles of the trace analyte. Additionally, the coating106 leaves no residue when the trace analyte collection area 104 isplaced against the surface to be swabbed. For dry particles, the coating106 improves the collection (pick-up or “harvesting”) efficiency of theswab 100 from the surface being swabbed compared to swabs that are notprovided with the coating 106. The coating 106 microscopically adheresthe collected particles of the trace analyte to the swab 100 so thatcollected particles do not become dislodged and fall from the swab 100during detection. Moreover, the coating 106 may retain volatile tracechemicals that would otherwise rapidly evaporate. The coating 106withstands exposure to high temperatures without degradation, permittinguse of the trace analyte collection swab 100 with a heated detector.Further, the coating, when heated, has limited or no outgassing ofvolatile materials that might otherwise contaminate a collected sample.

In embodiments, the coating 106 comprises a dopant such as a tracechemical that may be subsequently released during desorption by thedetector. It is contemplated that a variety of dopants may be applied tothe coating 106. For example, in an embodiment, the dopant may comprisea calibrating material for calibration of a detector. In anotherembodiment, the dopant may comprise a reactant material configured tocombine with the particles of trace analyte when the swab 100 is placedagainst a surface to be sampled. The reactant material may, far example,help to collect particles of a trace analyte from a surface, help toadhere particles of a trace analyze to the swab 100, and/or help todesorb particles of a trace analyte from the swab 100. In anotherembodiment, the dopant may comprise a vapour-collecting materialconfigured to collect particles of the trace analyte in vapour formwhich are subsequently released upon heating or desorption. Examplevapour-adsorbing materials include charcoal, a chromatographicabsorption material such as TENAX, and so forth. In another embodiment,the dopant may comprise a tracer material that can be used to indicatecharacteristics of the swab 100 when desorbed. For example, the coating106 may be doped with a tracer material to verify the authenticity ofthe swab 100. The coating 106 may also be doped with a tracer materialto indicate the suitability of the swab for collecting the traceanalyte. The coating may further be doped with a tracer material thatindicates the life of the swab 100 in multiple use applications (e.g.,indicates when the swab 100 has exceeded its useful life). The coating106 may also be doped with a tracer material to furnish a valid minimumresponse when used in combination with a detector to indicate correctoperation of the detector.

In embodiments, the coating 106 is applied over a limited portion (e.g.,area) of the trace analyte collection area 104 so that collectedparticles of trace analyte are concentrated for delivery to a detectorfor desorption of the trace analyte. For example, the position and areacovered by the coating 106 may at least substantially match the positionand area of the inlet opening of the detector with which the swab 100 isused. In the embodiment illustrated in FIG. 1, the coating 106 isapplied over a circular area of the trace analyte collection area 104 ofthe substrate 102. In one specific example, the circular area has adiameter of approximately 1.905 cm (0.75 in). However, it iscontemplated that the portion of the substrate 102 over which thecoating 106 is applied may have other shapes and surface areas.

In embodiments, the coating 106 is applied in a pattern 108 on thesubstrate 102 in the trace particle collection area 104. FIGS. 3, 4, and5 illustrate example trace analyte collection swabs 100, wherein thecoating 106 is patterned. As shown, the pattern 108 may comprise one ormore first areas 110 where the coating 106 is applied and one or moresecond areas 112 where the coating is not applied. The one or more firstareas 110 are configured to collect particles of a trace analyte of afirst type, while the one or more second areas are configured to collectparticles of a trace analyte of a second type. Thus, for example, thecoating 106 may be applied to one or more first areas 110 to collectparticles of dry chemicals such as TNT which do not efficiently adhereto the uncoated swab surface, while the second areas 112 where thecoating is not applied may collect particles of sticky trace chemicalsthat adhere to the uncoated swab surface more efficiently than to thecoating 106, or do not adhere to the coating 106. Additionally, thesecond areas 112 allow the swab surface to be exposed so that the swabmaterial, which may be absorbent, can wick away traces of moisture thatmight otherwise contaminate or suppress the collection of traceanalytes. Moreover, patterning of the coating 106 can facilitateprinting of indicia such as, directions for use of the swab, a barcode,a logo or other marketing information, and so forth. FIGS. 3, 4 and 5illustrate different coating patterns 108. In FIG. 3, the coating 106 ispatterned so that the first areas 110 and the second areas 112 compriseinterspersed concentric rings (e.g., the coating 102 is patterned in a“target” pattern). In FIG. 4, the first areas 110 and the second areas112 are arranged in alternating squares (e.g., the coating 106 ispatterned in a “checkerboard” pattern 108). In FIG. 5, the first areas110 and the second areas 112 are patterned in alternating strips (e.g.,the coating 106 is patterned in a spaced-apart bar pattern 108). Otherpatterns 108 may also be employed.

In embodiments, the coating 106 may be clear or translucent. In otherembodiments, the coating 106 may be tinted so that the substrate 102 mayhave a first color and the coating 106 may have a second color, whereinthe second color is different than the first color. In this manner,coating 106 of the swab 100 may function to indicate which side of theswab 100 to use to collect a sample, the location on the substrate 102to which to apply swabbing pressure (e.g., on the surface opposite thecoating 106 behind the trace analyte collection area 104), the correctlocation of the swab 100 in a sampling wand, and so forth. FIGS. 6 and 7illustrate example trace analyte collection swabs 100, wherein thesubstrate 102 has a first color and the coating 106 has a second colordifferent than the first color. In FIG. 6, the coating 106 is appliedover a circular area and is shown as being tinted blue against a whitesubstrate 102. In FIG. 7, the coating 106 is patterned with acheckerboard pattern 108 having first areas 110 provided with thecoating 106 and second areas 112 without the coating 106. The coating106, applied in the second areas 112 is shown as being tinted redagainst a white substrate 102 in the first areas 110. However, it iscontemplated that the coating 106 may be tinted in other colors,combinations of colors (e.g., green and yellow, red and blue, amulticolored logo, etc.), and so forth.

In embodiments, the substrate 102 of the trace analyte collection swab100 may be provided with an identifier 114, which may be machinereadable, such as a barcode, a Radio Frequency Identification (RFlD) tagor patch, identification indicia, combinations thereof, and so forth,for furnishing identification of the swab 100. For example, in FIG. 1,the substrate 102 is illustrated as including an identifier 114comprised of a two dimensional (2D) barcode. In embodiments, theidentifier 114 may be used to verify the authenticity of the swab 100,to indicate the suitability of the swab for collecting the traceanalyte, to indicate the life of the swab 100 in multiple useapplications (e.g., indicates when the swab 100 has exceeded its usefullife), and so forth.

In embodiments, a plurality of substrates 102 may be detachably joinedtogether in a trace analyte collection swab dispensing system configuredto dispense individual swabs 100. FIGS. 8 and 9 illustrate trace analytecollection swab dispensing systems 800, 900 in accordance with exampleembodiments of the present disclosure.

In the embodiment shown in FIG. 8, the trace analyte collection swabdispensing system 800 comprises a plurality of substrates 102 detachablyjoined together in a stacked arrangement. For example, a releasableadhesive 802 may be applied to an end portion of the surfaces ofrespective substrates 102 opposite the trace analyte collection area 104and coating 106 (e.g., the backside of the swab 100). However, it iscontemplated that, in embodiments, the coating 106 could be madesufficiently tacky to join the substrates 102 together without the useof an additional releasable adhesive 802. The releasable adhesive 802(or tacky coating 106) is configured to detachably join the bottomsurface respective substrates 102 to the top surface of an adjacentsubstrate 102 in the stacked arrangement. In this manner, the surface ofthe substrate 102 on which the coating 106 is disposed is occluded andthus protected from contamination. By occluding or protecting thesurface of the substrate 102 containing the coating 106, the cleaningprocesses typically employed for cleaning raw-material swabs in order tomake them suitable for use as a trace detection swab may be reduced oreliminated.

As shown in FIG. 8, the substrates 102 of the respective trace analytecollection swabs 100 may be provided with an identifier 114, which maybe machine readable, such as a barcode, an RFID tag or patch,identification indicia, combinations thereof, and so forth, forfurnishing identification of the swab 100. In embodiments, theidentifier 114 may be used to verify the authenticity of a swab 100 whendispensed, to indicate the suitability of the swab for collecting thetrace analyte, and so forth. In embodiments, the substrates 102 of therespective trace analyte collection swabs 100 may be configured forattachment to a sampling wand. For example, an adhesive may be disposedon the surface of the respective substrates 102 opposite the coating 106(e.g., on the reverse side of the trace analyte collection area 104 ofthe substrate 102) to facilitate attachment of the swab 100 to and/orremoval of the swab 100 from a sampling wand (not shown).

In the embodiment shown in FIG. 9, the trace analyte collection swabdispensing system 900 comprises a dispensing apparatus 902 containing aroll 904 of trace analyte collection swabs 100, wherein the respectivesubstrates 102 of the swabs 100 are joined end-to-end via a perforatedsection 906 (which may be generally V-shaped) within the roll 904. Theperforated sections 906 allow individual swabs 100 to be separated fromthe roll 904 for use. Again, the surface of the substrate 102 on whichthe coating 106 is disposed is occluded and thus protected fromcontamination so that the cleaning processes typically employed forcleaning raw-material swabs in order to make them suitable for use as atrace detection swab may be reduced or eliminated.

The trace analyte collection swab 100 may be fabricated as part of, ormay be attached to, another item or device that could be handled by anindividual leaving trace materials. In embodiments, the trace analytecollection swab 100 may comprise a portion of, or may be attached to, adocument such as an airline boarding pass, a ticket, and so forth. Forexample, as shown in FIG. 10, the substrate 102 of the trace analytecollection swab 100 is illustrated as comprising a portion of an airlineboarding pass 1000. In the embodiment illustrated, the boarding pass1000, or a portion thereof, is fabricated of a suitable substratematerial as described above and may include a portion 1002 that isretained by the airline, a governmental body such as the United StatesTransportation Security Administration (TSA), and so forth, and aportion 1004 that is provided to the traveler prior to boarding anaircraft. As shown, the retained portion 1002 includes a trace analytecollection area 104 positioned in an area of the boarding pass likely tobe handled by the traveler and a coating 106 disposed on the surface ofthe substrate 102 in the trace analyte collection area 104 to collecttrace analytes from the hands of the traveler for detection and/oranalysis. In other embodiments, the trace analyte collection swab 100may comprise a portion of the boarding pass 1000 that is removed andretained by the airline, governmental body, and so forth (e.g., apeelable sticker, a perforated section, and so forth), such as foranalysis. The boarding pass 1000 may further include an identifier 1006such as a bar code, RFID tag or patch, or the like, configured toassociate the particles of a trace analyte collected by the coating 106with the holder of the boarding pass 1000.

In other embodiments, the trace analyte collection swab 100 may comprisea portion of, or be attached to, a mailed item such as an envelope,package, and so forth. For example, as shown in FIG. 11, the substrate102 of the trace analyte collection swab 100 is illustrated ascomprising a portion of a package 1100. In the embodiment illustrated,the package 1100, or a portion thereof such as a flap 1102, isfabricated of a suitable substrate material as described above. However,in other embodiments, the substrate 102 may be adhered to the package1100 (e.g., via a peelable sticker, address label, stamp, and so forth),which may later be removed from the package 1100, such as for analysis.As shown, the package 1100 includes a trace analyte collection area 104(e.g., flap 1102) positioned in a portion of the package likely to behandled by the mailer (e.g., a person depositing the package in themail, a person handling the package prior to mailing, and so forth) whensealing the package and a coating 106 disposed on the surface of thesubstrate 102 in the trace analyte collection area 104 to collect traceanalytes from the hands of the mailer for detection and/or analysis. Inembodiments, the package 1100 may further include an identifier 1106such as a bar code, RFID tag or patch, or the like, configured toassociate the particles of a trace analyte collected by the coating 106with the mailer and/or a recipient of the package 1100.

in the embodiments described above, the substrate 102 of the traceanalyte collection swab has comprised a generally flat sheet ofsubstrate material. However, it is contemplated that the substrate 102need not necessarily be limited to this form factor. For example, thesubstrate 102 may be formed of a sheet of substrate material that isshaped (e.g., folded, rolled, embossed, etc.) into a three dimensionalshape (e.g., a cylinder, a cone, etc.). When formed into a threedimensional shape, the substrate 102 may be attached to a sampling wand,which may be configured to allow the trace analyte collection swab 100to be rolled against a surface to collect analyte from the surface.

For example, FIG. 12 illustrates a trace analyte collection swab 1200that includes a substrate 1202 that is generally triangular (e.g.,pie-shaped). As shown, the substrate 1202 may be rolled into a conehaving an outer surface that forms the trace analyte collection area1204 and a coating 1206 disposed on the substrate 1202 (e.g., on theouter surface of the cone) in the trace analyte collection area 1204.

Additionally, it is contemplated that non-sheet form factor substrates102 may be used. For example, shown in FIG. 13, the trace analytecollection swab 1300 illustrated comprises a brush 1302. In thisembodiment, the substrate is comprised of the bristles 1304 of the brush1302, which may be coated with a coating 1304 for collection ofparticles of trace analyte from a surface. The coating 1306 isconfigured to be microscopically adhesive to collect particles of thetrace analyte from a surface when the bristles 1304 of the brush areplaced (e.g., brushed) against the surface. In embodiments, the coatingcomprises Polyisobutylene (PIB) having a formulation such as PIB 4T orother PIB formulations. The PIB may have a molecular weight ofapproximately 59,000 GPC (Gel Permeation Chromatography). PIB (e.g., PIB4T or other PIB formulation) is not hazardous to humans or animals, canbe stored at room temperature indefinitely, readily dissolves in hexane,is stable in solution, and has substantially no pot-life.

The coating 1306, which, in embodiments, comprises PIB (e.g., PIB 4T orother PIB formulation), is not perceptibly tacky or sticky (e.g., thecoating 106 is dry-to-the-feel) and does not adhere to the surface beingsampled, but is microscopically adhesive (e.g., microscopically stickyor tacky) to particles of the trace analyte. Additionally, the coating1306 leaves substantially no residue when the bristles 1304 of the brushare placed (e.g., brushed) against the surface to be swabbed. Thecoating 1306 thus improves the collection (pick-up or “harvesting”)efficiency of the swab 1300 from the surface being swabbed compared toswabs that are not provided with the coating 1306. The coating 1306microscopically adheres the collected particles of the trace analyte tothe bristles 1304 of the swab 1300 so that collected particles do notbecome dislodged and fall from the swab 1300 during detection. Moreover,the coating 1306 may retain particles of volatile trace chemicals thatwould otherwise evaporate. The coating 1306 withstands exposure to hightemperatures without degradation, permitting use of the trace analytecollection swab 1300 with a heated detector. Further, the coating, whenheated, has limited or no outgassing of volatile materials that mightotherwise contaminate a collected sample.

In embodiments, the coating 1306 comprises a dopant such as a tracechemical that may be subsequently released during desorption by thedetector. It is contemplated that a variety of dopants may be applied tothe coating 1306. For example, in an embodiment, the dopant may comprisea calibrating material for calibration of a detector. In anotherembodiment, the dopant may comprise a reactant material configured tocombine with the particles of trace analyte when the swab 1300 is placedagainst a surface to be sampled. The reactant material may, for example,help to collect particles of a trace analyte from a surface, help toadhere particles of a trace analyte to the swab 1300, and/or help todesorb particles of a trace analyte from the swab 1300. In anotherembodiment, the dopant may comprise a vapour-collecting materialconfigured to collect particles of the trace analyte in vapour formwhich are subsequently released upon heating or desorption. Examplevapour-collecting materials include charcoal, a chromatographicabsorption material such as TENAX, and so forth. In another embodiment,the dopant may comprise a tracer material that can be used to indicatecharacteristics of the swab 1300 when desorbed. For example, the coating1306 may be doped with a tracer material to verify the authenticity ofthe swab 1300, The coating 1306 may also be doped with a tracer materialto indicate the suitability of the swab for collecting the traceanalyte. The coating may further be doped with a tracer material thatindicates the life of the swab 1300 in multiple use applications (e.g.,indicates when the swab 100 has exceeded its useful life). The coating1306 may also be doped with a tracer material to furnish a valid minimumresponse when used in combination with a detector to indicate correctoperation of the detector.

In embodiments, the brush 1302 can be capped so that particles of traceanalyte collected remotely can be protected from subsequentcontamination. The brush 1302 may be capable of reuse (e.g., following asuitable cleaning process). In embodiments, the brush 1302 is insertedinto the inlet area of a detector directly, and heated radiatively orthrough convection. In other embodiments, the material from which thebristles 1304 of the brush 1302 are fabricated may be conductive toallow for resistive heating of the coated bristles 1304, providingincreased control over the heating process. In this manner, heating athigher temperatures than would be achieved using a heated inlet may bepossible. Additionally, the use of resistive heating may allow fortemperature ramping at a much greater rate than is achievable using aramped-temperature or fixed temperature inlet. In this manner, therelease of the collected particles of trace analyte as vapour would befaster than with a ramped-temperature or fixed temperature inlet,providing a higher signal amplitude, and thus a better limit ofdetection.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Althoughvarious configurations are discussed the apparatus, systems, subsystems,components and so forth can be constructed in a variety of ways withoutdeparting from this disclosure. Rather, the specific features and actsare disclosed as example forms of implementing the claims.

What is claimed is:
 1. A trace analyte collection swab comprising: a substrate comprising an aramid polymer, the substrate comprising a surface defining a total surface area and a trace analyte collection area, the trace collection area being smaller than the total surface area, the trace collection area to be placed in contact against a surface from which the trace analyte is collected; and a coating disposed on the surface of the substrate in the trace analyte collection area, the coating comprising polyisobutylene to collect particles of the trace analyte from a surface when the trace analyte collection area is placed against the surface, wherein the trace analyte collection area comprises a first area where the coating is applied and a second area where the coating is not applied, and wherein the coating is applied over a limited portion of the trace analyte collection area to concentrate the trace analyte in the limited portion of the trace analyte collection area for delivery to an inlet of a detector and wherein the first area where the coating is applied and the second area where the coating is not applied are contactable against the surface from which the trace analyte is collected.
 2. The trace analyte collection swab as recited in claim 1, wherein the substrate has a first color and the coating has a second color, the second color being different than the first color.
 3. The trace analyte collection swab as recited in claim 1, wherein the coating comprises a dopant.
 4. The trace analyte collection swab as recited in claim 3, wherein dopant comprises a calibrating material.
 5. The trace analyte collection swab as recited in claim 3, wherein the dopant comprises a reactant material configured to combine with the particles of the trace analyte.
 6. The trace analyte collection swab as recited in claim 3, wherein the dopant comprises a tracer material.
 7. The trace analyte collection swab as recited in claim 3, wherein the dopant comprises a vapour-collecting material, the vapour-collecting material configured to collect particles of the trace analyte in vapour form.
 8. The trace analyte collection swab as recited in claim 1, wherein the substrate comprises an identifier configured to furnish identification of the trace analyte collection swab.
 9. The trace analyte collection swab as recited in claim 1, wherein the substrate comprises a boarding pass, the boarding pass including a bar code, the bar code configured to associate the particles of the trace analyte collected by the coating with the holder of the boarding pass.
 10. The trace analyte collection swab as recited in claim 1, wherein the substrate comprises a package including a bar code, the bar code configured to associate the particles of the trace analyte collected by the coating with the mailer of the package.
 11. The trace analyte collection swab as recited in claim 1, wherein the substrate comprises one or more bristles of a brush.
 12. A trace analyte collection swab comprising: a substrate including a surface having a trace particle collection area to be placed against a surface from which the trace analyte is collected; and a coating of Polyisobutylene disposed on the surface of the substrate in the trace particle collection area, the coating configured to be microscopically adhesive to collect particles of the trace analyte from a surface when the trace particle collection area is placed against the surface; wherein the coating is applied in a pattern on the substrate in the trace particle collection area, the pattern comprising at least one first area where the coating is not applied and at least one second area where the coating is applied, the at least one first area configured to collect particles of a trace analyte of a first type and the at least one second area configured to collect particles of a trace analyte of a second type where the particles of a trace analyte of a second type are collected less efficiently by the at least one first area than by the at least one second area.
 13. The trace analyte collection swab as recited in claim 12, wherein the substrate comprises at least one of paper or an aramid polymer.
 14. A method of collecting trace analytes for analysis comprising: contacting a trace analyte collection area of a swab with a surface to collect trace analyte from the surface, wherein the trace analyte collection area comprises a coating comprising polyisobutylene for collecting the trace analyte from the surface, and wherein the coating is applied over a limited portion of the trace analyte collection area to concentrate the trace analyte in the limited portion of the trace analyte collection area for delivery to an inlet of a detector and wherein all of the trace analyte collection area is contactable against the surface from which the trace analyte is collected; and heating the swab to vaporise and desorb the trace analyte for analysis.
 15. The method as recited in claim 14, further comprising analysing the trace analyte.
 16. The method as recited in claim 15, wherein analysing the trace analyte comprises at least one of ion mobility spectrometry, mass spectrometry, gas chromatography, liquid chromatography, and high performance liquid chromatography.
 17. The method as recited in claim 14, wherein the heating comprises resistive heating of the swab.
 18. The method as recited in recited in any one of claim 14, wherein the coating comprises a dopant.
 19. The method as recited in claim 18, wherein dopant comprises at least one of a calibrating material, a reactant material configured to combine with the particles of the trace analyte, a tracer material, or a vapour-collecting material, the vapour-collecting material configured to collect particles of the trace analyte in vapour form.
 20. The method as recited in claim 14, further comprising identifying the swab using an identifier on the swab. 